Voice coil motor comprising a magnet fixing structure

ABSTRACT

A camera module is disclosed, the camera module including a PCB (Printed Circuit Board), a base arranged at an upper surface of the PCB, a holder member arranged at an upper surface of the base and formed with a plurality of magnet reception portions, a surface of which facing the base is opened, and a plurality of magnets coupled to the magnet reception portions, wherein the base is formed with a protrusion configured to support a bottom surface of the magnet by being protrusively formed at a position corresponding to an opening of the magnet reception portions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/324,588, filed Jul. 7, 2014; which claims the benefit under 35 U.S.C.§ 119 of Korean Application No. 10-2013-0078498, filed Jul. 4, 2013,which are hereby incorporated by reference in their entirety.

BACKGROUND

Field of the Disclosure

The present disclosure relates to a camera module.

Background of the Related Art

A camera module may include an optical system comprising at least onelens. At this time, the optical system may include an actuator moduleconfigured to perform an auto-focusing function and hand-shakecorrection function.

The actuator module may be variably configured and generally uses a VCM(Voice Coil Motor). The VCM can perform an auto-focusing function bybeing operated through electromagnetic interaction between a magnetsecured on a holder member and a coil wound on a periphery of a bobbinreciprocally arranged at a lens barrel side.

At this time, a lateral wall of the holder member of the VCM is formedwith a through hole corresponding to the magnet in terms of shape, andthe through hole is adhesively fixed by the magnet using an adhesivemember. In order to form a through hole on the holder member, it isessential to use a slide core on an injection-molded holder member withresin. A manufacturing cost of a mold having a slide core used forforming a through hole at a lateral surface is higher cost-wise 10 to 15times than a general injection mold, which eventually results inincreased manufacturing cost of parts. Furthermore, another disadvantageis that there is a high possibility of foreign objects being introducedinto camera module due to short gap path formed by a shield can, a baseand a holder member.

BRIEF SUMMARY

Accordingly, the present disclosure has been made keeping in mind theabove disadvantages/problems occurring in the prior art, and it is anobject of the present disclosure to provide a camera module configuredto reduce a manufacturing cost of mold and to minimize introduction offoreign objects.

Advantageous Effects

In one general aspect of the present disclosure, there is provided acamera module, the camera module comprising:

a PCB (Printed Circuit Board);

a base arranged at an upper surface of the PCB;

a holder member arranged at an upper surface of the base and formed witha plurality of magnet reception portions, a surface of which facing thebase is opened; and

a plurality of magnets coupled to the magnet reception portions, whereinthe base is formed with a protrusion configured to support a bottomsurface of the magnet by being protrusively formed at a positioncorresponding to an opening of the magnet reception portions.

Preferably, but not necessarily, the base may be formed with theprotrusions to allow a distance between an upper surface of the magnetreception portion and the protrusion to have a width corresponding to aheight of the magnet when the base and the holder member are coupled.

Preferably, but not necessarily, the protrusion and the magnet may havea mutually corresponding width.

Preferably, but not necessarily, the base may be configured such that aninsertion groove is formed at a surrounding of the protrusion, and theholder member is configured such that an insertion lug is formed at aposition corresponding to that of the insertion groove.

Preferably, but not necessarily, the base may be formed at a corner areabased on a bottom surface with a convex part formed higher than theprotrusion, and the holder member is formed with a concave part at aposition corresponding to that of the convex part.

Preferably, but not necessarily, a surface of the magnet facing theholder member may have a polarity different from that of a surface ofthe magnet facing the base.

Preferably, but not necessarily, the camera module may further comprisea shield can that is coupled to the base to accommodate the holdermember therein.

Preferably, but not necessarily, the shield can may be formed with ametal material to accommodate therein the convex part formed on thebase, the insertion groove and the protrusion. Preferably, but notnecessarily, the base may be formed with a hitching part coupled to theshield can and the hitching part may be protrusively formed outside ofthe convex part, the insertion groove and the protrusion.

Preferably, but not necessarily, the base may include an insertiongroove formed at a surrounding of the protrusion, and a convex partprotrusively formed at a corner area, and the holder member may includean insertion lug formed at a position corresponding to that of theinsertion groove and a concave part formed at a position correspondingto that of the convex part, and the holder member may be so formed as toallow the magnet reception portion, the concave part and the insertionlug to be arranged in the order of increasing height based on an uppersurface of the holder member.

The camera module according to exemplary embodiments of the presentdisclosure has an advantageous effect in that the magnet receptionportion of the holder member is formed at a surface facing the base withan opening, not in the shape of a through hole to dispense with a moldusing a slide core, whereby a manufacturing cost can be reduced.

Another advantageous effect is that a surface facing the magnet of thebase is extended to allow a distal end of the base to directly contactthe magnet, whereby foreign object intake path leading to the magnetreception portion coupled to the shield can, the base and the holdermember is relatively lengthened to minimize inflow of foreign objects.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an exemplary view illustrating a configuration of a cameramodule according to an exemplary embodiment of the present disclosure,

FIG. 2 is an exploded view illustrating a coupled relationship between aholder member and a base of FIG. 1, and

FIG. 3 is a schematic view illustrating a coupled relationship of a baseaccording to another exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings.

FIG. 1 is an exemplary view illustrating a configuration of a cameramodule according to an exemplary embodiment of the present disclosure,FIG. 2 is an exploded view illustrating a coupled relationship between aholder member and a base of FIG. 1, and FIG. 3 is a schematic viewillustrating a coupled relationship of a base according to anotherexemplary embodiment of the present disclosure.

FIG. 1 is an exemplary view illustrating a configuration of a cameramodule according to an exemplary embodiment of the present disclosure.

Referring to FIG. 1, the camera module according to an exemplaryembodiment of the present disclosure may include a PCB (10), a base(20), a holder member (30), a shield can (40) and a lens part (50). Theexemplary embodiment of the present disclosure is a camera module havinga VCM as an actuator.

The PCB (10) may include an image sensor (not shown) and may beconnected to an electronic device such as a mobile device. To be morespecific, the PCB (10) may apply an electric power for driving a VCM.The image sensor (not shown) may be mounted at a center of an uppersurface of the PCB (10) to allow being positioned along an opticaldirection with one or more lenses (not shown) accommodated inside thelens part (50, described later). The image sensor serves to convert anoptical signal of an object incident through a lens to an electricsignal.

The base (20) is arranged at an upper surface of the PCB (10), and maybe arranged with a filter at a position corresponding to that of theimage sensor. In this case, the filter may be mounted at a through holeformed at a center of the base (20), and may be provided with aninfrared ray filter or a blue filter. At this time, the filter may beformed with a film material or a glass material, for example, and may bearranged with a flat optical filter such as an imaging surfaceprotection cover glass or a cover glass coated with infrared blockingmaterial.

The holder member (30) is arranged therein with a lens holder configuredto support a plurality of lens parts (50), and a lens holder, and may bearranged with a vertically-movable bobbin wound at a periphery with acoil. Furthermore, the periphery of the holder member (30) may bearranged with a magnet (32) at a position corresponding to that of thecoil, and each surface of the holder member (30) may be formed with amagnet reception portion (31) in order to arrange the magnet (32).

According to an exemplary embodiment of the present disclosure, theholder member (30) may be arranged at an upper surface and a bottomsurface with an upper and bottom elastic members configured toelastically support a lifting operation of the bobbin, and the holdermember (30) may be formed at an upper surface with a through holecorresponding to an opening of the shield can (40), and formed with acoupling lug (35) coupled by the upper elastic member. Furthermore, theholder member (30) may be protrusively formed with at least two stoppers(36) configured to simultaneously maintain a discrete distance from theshield can (40, described later) and to protect the holder member (30)from outside shock, each of the at least two stoppers being spaced apartat a predetermined distance.

The holder member (30) may be formed at an upper surface with areception groove (37) where a part of the upper elastic member(described later) is to be accommodated. To be more specific, the upperelastic member (not shown) may be provided with a leaf spring which maybe arranged at an upper surface of the holder member (30), whereby theshield can (40) may be assembled therein with the upper elastic member,the holder member (30) and the magnet (32) in that order, the structureof which can greatly simplify an assembly process.

Alternatively, the holder member (30) may not be formed with thecoupling lug (35) and/or the reception groove (37), and the upperelastic member may be inserted into an inner surface of the holdermember (30). That is, the upper elastic member may take a shapecorresponding to that of the inner surface of the holder member (30),whereby the shield can (40) may be assembled therein with the holdermember (30), the upper elastic member and the magnet (32) in that order,the structure of which can greatly simplify an assembly process.

The shield can (40) may be coupled to the base (20) to close a bottomsurface and to form an exterior look of the camera module. The shieldcan (40) may receive the holder member (30) to prevent the holder member(30) from being exposed to the outside. The shield can (40) may beformed at an upper surface with an opening to be shaped in the form of acube or a rectangular parallelepiped that is opened at a bottom surface.However, the present disclosure is not limited thereto. The shield can(40) may be formed with a metal material to block an electromagneticwave generated from the camera module and to prevent an outside noisecomponent from entering the camera module. Thus, the shield can (40) maybe formed with a metal material such as iron or aluminum, and may beelectroplated with a metal such as nickel.

An inner surface of the shield can (40) facing the holder member (30)may be provided with support means configured to support the upperelastic member, and may be fixedly coupled by a separate cover member aswell.

The holder member (30) may be formed in a shape corresponding to that ofthe inner surface of the shield can (40), and in the exemplaryembodiment of the present disclosure, the magnet reception portion (31)formed at the holder member (30) may be provided in a shape of anopening opened at a distal end, and as illustrated in FIG. 2, the magnetreception portion (31) may be formed with an opening opened at a surfacefacing the base (20).

The magnet reception portion (31) may be formed at a position arrangedwith the magnet (32). When the holder member (30) is provided in asquare shape, the magnet (32) may be arranged at each surface of thesquared holder member (30) and therefore a total four magnet receptionportions (31) may be arranged. The magnet reception portion (31) may beformed in a size corresponding to that of the magnet (32) and may beformed in other sizes if necessary for design.

Each of the magnets (32) may be formed with a same magnetic force, andmay be formed with an N pole at an upper side and with a S pole at abottom side as illustrated in FIGS. 2 and 3, and a surface facing aperiphery of the holder member (30) and a surface facing an innersurface of the holder member (30) may be arranged with a mutuallydifferent magnetic pole.

The magnet (32) may be so formed at an outer surface as to contact aninner surface of the shield can (40), and may be so formed as to contactthe magnet support part (31), where each lateral surface faces the otherlateral surface. In the exemplary embodiment of the present disclosure,although it is described that the magnet support part (31) is formed ateach surface of the holder member (30) to allow each magnet to take ashape of a rectangular parallelepiped, each of the magnets may be formedin a bent shape of “

”, if the magnet support part (31) is formed at each corner of theholder member (30). Furthermore, the magnet may be so processed as tohave a curved surface at the time of processing.

The lens part (50) may be a lens barrel, but the present disclosure isnot limited thereto and any holder structure configured to support thelens may be acceptable. The present exemplary embodiment of the presentdisclosure exemplifies a case where the lens part is a lens barrel or abobbin coupled with a lens barrel. The lens part (50) may be arranged atan upper surface of the base (20), and arranged at a positioncorresponding to that of an image sensor (described later). The lenspart (50) may be arranged with one or more lenses (not shown).

The bobbin is coupled to the lens barrel to secure the lens barrel,where a coupling method between the lens barrel and the bobbin may use ascrew thread method by forming a screw thread on an inner surface of thebobbin and on a periphery of the lens part (50), but may use a non-screwthread method that uses adhesive. It should be apparent that an adhesivecan be used on the screw thread method for stronger coupling after thelens barrel and the bobbin are screwed.

The characteristic of the exemplary embodiment of the present disclosureis that the magnet reception portion (31) is not formed in the shape ofa through hole at the lateral surface of the holder member (30) informing the holder member (30), but formed to have an opened opening ata distal end unlike the conventional method, where a structure forsupporting a floor surface of the magnet (32) may be integrally providedon the base (20).

That is, as illustrated in FIGS. 2 and 3, the base (20) facing themagnet (32) may be formed with a protrusion (100) configured to becontacted to a bottom surface of the magnet (32). That is, the base (20)may be formed with the protrusion (100) that is protrusively formed at aposition corresponding to that of the opening of the magnet receptionportion (31) to support a bottom surface of the magnet (32).

To be more specific, the protrusion (100) may have a width correspondingto that of the magnet (32), and a distance from an upper surface of themagnet reception portion (31) to the protrusion (100) may have a widthcorresponding to a height of the magnet (32) when the base (20) and theholder member (30) are coupled.

When the base (20) is provided with the protrusion (100) as noted above,introduction of a foreign object into the camera module through acoupled surface between the base (20) and the shield can (40) can beminimized due to increased moving distance to a contact surface betweenthe magnet arranged at the holder member (30) and the protrusion (100).

Meantime, as illustrated in FIGS. 2 and 3, a surface of the base (20)and a surface of the holder member (30) that faces the surface of thebase (20) may take a corresponding shape. That is, a distal end of thebase (20) may be provided with a convex part (23), and the holder member(30) may be provided with a concave part (33) corresponding to theconvex part (23).

Furthermore, a concave insertion groove (24) may be formed between theprotrusion (100) of the base (20) and the convex part (23), and theholder member (30) corresponding to the insertion groove (24) may beformed with an insertion lug (34) longer than the concave part (33) ofthe holder member (30).

At this time, the insertion lug (34) may be protruded from the concavepart (33), and the insertion groove (24) may be concavely formed at theprotrusion (100). In short, the holder member (30) may be so formed asto allow the magnet reception portion (31), the concave part (33) andthe insertion lug (34) to increase in height in that order based on theupper surface of the holder member (30), and the base (20) is so formedas to allow the insertion groove (24), the protrusion (100) and theconvex part (23) to increase in height in that order based on the bottomsurface of the base (20). This structure can effectively prevent theforeign object from entering the camera module by forming a coupled lineof the base (20) and the holder member (30) in a complicated manner.

Furthermore, a surface or a corner of the insertion lug (34) of anoptical axis direction may take a curved shape formed by being spacedapart from the lens part (50) at a predetermined distance in order toremove interference when the lens part (50, described later) moves to anoptical direction. The shape may be formed in the same way as for eachsurface of the base (20) and the holder member (30), but may take adifferently depending on design purpose.

Meantime, the base (20) may be formed with a hitching part (25) coupledby the shield can (40), and the hitching part (25) may be protrusivelyformed from a lateral surface of the base (20) toward an outside of theconvex part (23), the insertion groove (24) and the protrusion (100).Furthermore, the base (20) may be protrusively formed from a bottomsurface with at least one mounting lug (26) that is mounted at a concavegroove of the PCB (10).

According to the exemplary embodiment of the present disclosure, nosliding core is required on a mold during injection molding of theholder member (30) because the magnet reception portion (31) of theholder member (30) supporting the magnet (32) is provided, not in theshape of a through hole, but in the shape of an opened opening. Thus,the holder member (30) can be manufactured at a relatively low priceusing a general mold whereby a manufacturing cost of holder member (30)can be reduced.

Furthermore, the insertion process of magnet (32) used to be manuallyperformed can be automated because the base (20), the magnet (32) andthe holder member (30) can be assembled to a same direction. Stillfurthermore, the introduction of foreign object can be minimized becausea foreign object moving distance is relatively lengthened, and because acoupled position between the magnet (32) and the protrusion (100) can bearranged at a location higher than that of a conventional coupledposition between the holder member (30) and the base (20).

The above-mentioned camera module according to exemplary embodiments ofthe present disclosure and attached drawings may, however, be embodiedin many different forms and should not be construed as limited to theembodiment set forth herein. Thus, it is intended that embodiment of thepresent disclosure may cover the modifications and variations of thisdisclosure provided they come within the scope of the appended claimsand their equivalents.

What is claimed is:
 1. A voice coil motor, the voice coil motorcomprising: a holder member; a lens holder disposed in the holdermember; a base disposed below the holder member; a coil disposed on thelens holder; and a magnet disposed on the holder member and facing thecoil, wherein the holder member comprises an opened-bottom magnetreception part accommodating the magnet and a lug supporting a lateralsurface of the magnet, and wherein the base comprises a protrusionsupporting a lower surface of the magnet, and a groove next to theprotrusion and accommodating at least a portion of the lug.
 2. The voicecoil motor of claim 1, wherein the lateral surface of the magnet iscompletely overlapped with the holder member in a horizontal directionfrom an upper end of the magnet to a bottom end of the magnet.
 3. Thevoice coil motor of claim 2, wherein the lateral surface of the magnetis completely overlapped with the holder member in a horizontaldirection from an outer end of the magnet to an inner end of the magnet.4. The voice coil motor of claim 1, wherein the magnet comprises anupper surface surface-contacted with the holder member, wherein thelower surface of the magnet is surface-contacted with the base, andwherein the lateral surface of the magnet is surface-contacted with theholder member.
 5. The voice coil motor of claim 1, wherein the basecomprises a convex part formed higher than an upper surface of theprotrusion of the base, and wherein the holder member comprises aconcave part formed at a position corresponding to that of the convexpart.
 6. The voice coil motor of claim 1, wherein an upper surface ofthe magnet facing the holder member has a polarity different from thatof the lower surface of the magnet facing the base.
 7. The voice coilmotor of claim 5, wherein the holder member is so formed as to allow themagnet reception part, the concave part, and the lug to be arranged inan order of increasing height with respect to an upper surface of theholder member.
 8. The voice coil motor of claim 1, further comprising ashield can coupled to the base and accommodating the holder membertherein.
 9. The voice coil motor of claim 8, wherein the shield can isformed with a metal material and accommodates a portion of the basetherein.
 10. The voice coil motor of claim 8, wherein the base is formedwith a hitching part coupled to the shield can, and wherein the hitchingpart is protrusively formed outside of the base.
 11. A camera module,the camera module comprising: a PCB (Printed Circuit Board); an imagesensor disposed on the PCB; the voice coil motor of claim 1 disposed onthe PCB; and a lens coupled with the lens holder of the voice coilmotor.
 12. A mobile device, comprising the camera module of claim 11.13. The voice coil motor of claim 1, wherein the protrusion of the baseand the magnet have a mutually corresponding width.
 14. The voice coilmotor of claim 1, wherein a lower end of the lug is disposed at aposition lower than that of the lower surface of the magnet.
 15. A voicecoil motor, the voice coil motor comprising: a holder member; a lensholder disposed in the holder member; a base disposed under the holdermember; a coil disposed on the lens holder; a magnet disposed at aposition corresponding to that of the coil, wherein the holder membercomprises an opened-bottom magnet reception part accommodating themagnet and a lug supporting a lateral surface of the magnet, wherein alower end of the lug is disposed at a position lower than that of alower surface of the magnet, and wherein the base comprises a protrusionsupporting the lower surface of the magnet.
 16. The voice coil motor ofclaim 15, wherein the base comprises a groove next to the protrusion,and wherein at least a portion of the lug is disposed in the groove ofthe base.
 17. The voice coil motor of claim 15, wherein the basecomprises a convex part formed higher than an upper surface of theprotrusion of the base, and wherein the holder member comprises aconcave part formed at a position corresponding to that of the convexpart.
 18. A voice coil motor, the voice coil motor comprising: a holdermember; a lens holder disposed in the holder member; a base disposedunder the holder member and comprising a recess; a coil disposed on thelens holder; a magnet disposed between the holder member and the baseand facing the coil, wherein the holder member comprises anopened-bottom magnet reception part accommodating the magnet and a lugsupporting a portion of a lateral surface of the magnet, wherein a lowersurface of the magnet is disposed on an upper surface of the base, andwherein the recess of the base is recessed from the upper surface of thebase, and the lug is disposed in the recess of the base.
 19. The voicecoil motor of claim 18, wherein the recess of the base is formed next tothe protrusion.
 20. The voice coil motor of claim 18, wherein the basecomprises a convex part formed higher than the upper surface of thebase, and wherein the holder member comprises a concave part formed at aposition corresponding to that of the convex part.